Perturbation of Hsp90 interaction with nascent CFTR prevents its maturation and accelerates its degradation by the proteasome

Melinda A. Loo, Timothy J. Jensen, Liying Cui, Yue Xian Hou, Xiu-Bao D Chang, John R. Riordan

Research output: Contribution to journalArticle

281 Citations (Scopus)

Abstract

Maturation of wild-type CFTR nascent chains at the endoplasmic reticulum (ER) occurs inefficiently; many disease-associated mutant forms do not mature but instead are eliminated by proteolysis involving the cytosolic proteasome. Although calnexin binds nascent CFTR via its oligosaccharide chains in the ER lumen and Hsp70 binds CFTR cytoplasmic domains, perturbation of these interactions alone is without major influence on maturation or degradation. We show that the ansamysin drugs, geldanamycin and herbimycin A, which inhibit the assembly of some signaling molecules by binding to specific sites on Hsp90 in the cytosol or Grp94 in the ER lumen, block the maturation of nascent CFTR and accelerate its degradation. The immature CFTR molecule was detected in association with Hsp90 but not with Grp94, and geldanamycin prevented the Hsp90 association. The drug-enhanced degradation was decreased by lactacystin and other proteasome inhibitors. Therefore, consistent with other examples of countervailing effects of Hsp90 and the proteasome, it would seem that this chaperone may normally contribute to CFTR folding and, when this function is interfered with by an ansamycin, there is a further shift to proteolytic degradation. This is the first direct evidence of a role for Hsp90 in the maturation of a newly synthesized integral membrane protein by interaction with its cytoplasmic domains on the ER surface.

Original languageEnglish (US)
Pages (from-to)6879-6887
Number of pages9
JournalEMBO Journal
Volume17
Issue number23
StatePublished - Dec 1 1998

Fingerprint

Proteasome Endopeptidase Complex
Endoplasmic Reticulum
Degradation
Calnexin
Association reactions
Rifabutin
Proteolysis
Proteasome Inhibitors
Molecules
Oligosaccharides
Pharmaceutical Preparations
Cytosol
Membrane Proteins
geldanamycin

Keywords

  • Ansamycin
  • CFTR
  • ER degradation
  • Hsp90
  • Proteasome

ASJC Scopus subject areas

  • Genetics
  • Cell Biology

Cite this

Loo, M. A., Jensen, T. J., Cui, L., Hou, Y. X., Chang, X-B. D., & Riordan, J. R. (1998). Perturbation of Hsp90 interaction with nascent CFTR prevents its maturation and accelerates its degradation by the proteasome. EMBO Journal, 17(23), 6879-6887.

Perturbation of Hsp90 interaction with nascent CFTR prevents its maturation and accelerates its degradation by the proteasome. / Loo, Melinda A.; Jensen, Timothy J.; Cui, Liying; Hou, Yue Xian; Chang, Xiu-Bao D; Riordan, John R.

In: EMBO Journal, Vol. 17, No. 23, 01.12.1998, p. 6879-6887.

Research output: Contribution to journalArticle

Loo, MA, Jensen, TJ, Cui, L, Hou, YX, Chang, X-BD & Riordan, JR 1998, 'Perturbation of Hsp90 interaction with nascent CFTR prevents its maturation and accelerates its degradation by the proteasome', EMBO Journal, vol. 17, no. 23, pp. 6879-6887.
Loo, Melinda A. ; Jensen, Timothy J. ; Cui, Liying ; Hou, Yue Xian ; Chang, Xiu-Bao D ; Riordan, John R. / Perturbation of Hsp90 interaction with nascent CFTR prevents its maturation and accelerates its degradation by the proteasome. In: EMBO Journal. 1998 ; Vol. 17, No. 23. pp. 6879-6887.
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